Submission #768517

#	Time	Username	Problem	Language	Result	Execution time	Memory
768517		raysh07	Travelling Merchant (APIO17_merchant)	C++17	100 / 100	74 ms	4432 KiB

merchant

#include <bits/stdc++.h>
using namespace std;
#define int long long
#define INF (int)1e18
#define f first
#define s second

mt19937_64 RNG(chrono::steady_clock::now().time_since_epoch().count());

int n, m, k;
const int N = 101;
const int K = 1e3 + 1;
int buy[N][K];
int sell[N][K];
vector <pair<int, int>> adj[N];
int floyd[N][N];
int best[N][N];

bool check(int x){
    vector<vector<int>> ok(n + 1, vector<int>(n + 1, -INF));
    
    for (int i = 1; i <= n; i++){
        for (int j = 1; j <= n; j++){
            if (floyd[i][j] == INF) continue;
            
            ok[i][j] = max(ok[i][j], best[i][j] - x * floyd[i][j]);
        }
    }
    
    for (int k = 1; k <= n; k++){
        for (int i = 1; i <= n; i++){
            for (int j = 1; j <= n; j++){
                ok[i][j] = max(ok[i][j], ok[i][k] + ok[k][j]);
                if (ok[i][j] > INF) ok[i][j] = INF;
            }
        }
    }
    
    for (int i = 1; i <= n; i++){
        for (int j = 1; j <= n; j++){
            if (i != j && ok[i][j] + ok[j][i] >= 0) return true;
        }
    }
    
    return false;
}

void Solve() 
{
    cin >> n >> m >> k;
    for (int i = 1; i <= n; i++){
        for (int j = 1; j <= k; j++){
            cin >> buy[i][j] >> sell[i][j];
            if (buy[i][j] == -1) buy[i][j] = INF;
            if (sell[i][j] == -1) sell[i][j] = 0;
        }
    }
    
    for (int i = 0; i < N; i++){
        for (int j = 0; j < N; j++){
            floyd[i][j] = INF;
        }
    }
    
    for (int i = 1; i <= m; i++) {
        int u, v, w; cin >> u >> v >> w;
        
        adj[u].push_back({v, w});
        floyd[u][v] = w;
    }
    
    for (int k = 1; k <= n; k++){
        for (int i = 1; i <= n; i++){
            for (int j = 1; j <= n; j++){
                floyd[i][j] = min(floyd[i][j], floyd[i][k] + floyd[k][j]);
            }
        }
    }
    
    for (int i = 1; i <= n; i++){
        for (int j = 1; j <= n; j++){
            for (int i1 = 1; i1 <= k; i1++){
                best[i][j] = max(best[i][j], sell[j][i1] - buy[i][i1]);
            }
        }
    }
    
    int lo = 0, hi = 1e9;
    while (lo != hi){
        int mid = (lo + hi + 1) / 2;
        
        if (check(mid)) lo = mid;
        else hi = mid - 1;
    }
    
    cout << lo << "\n";
}

int32_t main() 
{
    auto begin = std::chrono::high_resolution_clock::now();
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int t = 1;
  //  cin >> t;
    for(int i = 1; i <= t; i++) 
    {
        //cout << "Case #" << i << ": ";
        Solve();
    }
    auto end = std::chrono::high_resolution_clock::now();
    auto elapsed = std::chrono::duration_cast<std::chrono::nanoseconds>(end - begin);
    cerr << "Time measured: " << elapsed.count() * 1e-9 << " seconds.\n"; 
    return 0;
}

• Subtask 1: 12 / 12
• Subtask 2: 21 / 21
• Subtask 3: 33 / 33
• Subtask 4: 34 / 34